Registering printing plates



May 27, 1969 s. A. WEEKS ETAL 3,446,145

REGISTERING PRINTING PLATES ors Sheet Filed Feb. 23 1967 5 4 a m a 5% .vaJ/W... a m

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May 27, 1969 s. A. WEEKS ET AL. 3,446,145

REGISTERING PRINTING PLATES Sheet 3 013 Filed Feb. 23, 1967 May 27, 1969s. A. WEEKS L REGISTERING PRINTING PLATES Filed Feb. 25, 1967 Sheet 3 ors Z5 Z1 Z1 Z2 ,zg 1 I 1 I United States Patent US. Cl. 101426 12 ClaimsABSTRACT OF THE DISCLOSURE A method and apparatus of laying printingplates or blocks on to a backing sheet or directly on to a forme byplacing the layout or copy on a layout board using a transparenttransfer sheet to obtain an image and aligning the image with the layoutor copy so that on transferring the plate or block from a plate holdingthe positioning frame to the backing sheet or forme exact registrationwith the layout can be obtained.

This invention relates to a method of laying printing plates and blocksand an apparatus for use therewith.

One of the difliculties with which a printer is confronted is that ofaccurately positioning printing plates when mounting them onto the formeor onto a backing sheet, so that they are in exact registration with thecopy or layout. This is usually done by measurement to obtain theapproximate position and involves the pulling and ruling up of proofsuntil the exact position has been obtained: a time-wasting processduring which the press is standing idle.

A method of laying printing plates or blocks on to a backing sheet oronto a forme according to the invention comprises,

(1) placing the layout or copy on a layout board;

(II) setting up a backing sheet or mount to receive the plates orblocks, said layout board and backing sheet or mount being arranged forrelative movements into or out of an operative position;

(III) releasably attaching a plate to a holding means;

(IV) aligning a transparent image transfer sheet with the holding means;

(V) obtaining an image of the plate attached to the holding means on thetransparent image transfer sheet;

(VI) superimposing the image so obtained on its counterpart in thelayout;

(VII) aligning the holding means with the image transfer sheet with theplate face downwards on its holding means and;

(VIII) transferring the plate to the backing sheet or direct to the formand repeating the operation until all the plates are correctly laid.

It will be appreciated that by repeating this method of laydown, each ofthe plates or blocks can readily be located in its correct position onthe backing sheet or mount, since by aligning the image of each platewith the layout it follows that the plate must be accurately position onthe backing sheet or mount when transferred thereto.

Apparatus for carrying out the method of this invention makes use of twocomponents, the one embodying a backing sheet and layout board and thesecond a holding means for the plates and transfer sheet by which animage of the plate being layed is obtained and used in transferring theplates individually to the backing sheet or direct to the forme.

The first component may comprise a layout board surrounded by a coversheet frame bearing a transparent cover sheet for covering andprotecting the layout during the mounting operation. Hingedly attachedto one side of the said frame is means, such as a clamp, for holding thebacking sheet on which the plates are to be laid, or the forme memberwhen the plates are transferred directly thereto. The provision of thehinge also enables the cover sheet frame to be lifted up into contactwith the backing sheet or with a mount placed behind or beside theapparatus.

The second component may be made up of two similar frames which arepreferably hingedly inter-connected, one frame for use as the holdingmeans being fitted with a holding sheet of carbonised plastic or othercopying material on which the plate is adhered face down on theuncarbonised side, and the other frame with a sheet of transparent filmor tracing material onto which an image of the plate is transferred.

Alternatively, the plate holding sheet need not be carbonised, in whichcase the plate may be attached to it face up and a separate carbon sheetor some other copying method used, e.g. the plate could be inked.

The invention is illustrated in the accompanying drawings in which:

FIGURE 1 is a diagrammatic perspective view showing the working surfaceand its associated backing sheet on which the plates to be laid aremounted;

FIGURE 2 is a plan view to a larger scale of the holding and transferframes;

FIGURE 3 is a. plan view, and

FIGURES 4 and 5, front elevation and section views of the register frameand clamp device shown in FIGURE 1;

FIGURES 6 and 7 are detail plan and elevation views showing analternative form of holding and transfer frame unit;

FIGURE 8 is an elevation of a positioning frame device primarily forlaying colour half-tone plates;

FIGURE 9 is a side elevation of a back-rest for the backing sheet.

Referring first to FIGURES 1 and 2, the apparatus for carrying out themethod of laying printing plates or blocks in accordance with thisinvention comprises a layout board 1 on which a layout, indicatedgenerally at L of the copy to be printed is placed, the board 1 beingenclosed within a metal frame 2 for holding in position a transparentcover sheet 2 for protecting the layout during the plate mountingoperation. For convenience the board 1 is mounted on a baseboard 10 asshown.

Associated with the layout board 1 is a sheet 3 termed a backing sheeton which the plates are to be mounted in positions which correspondprecisely with the positions of their counterparts on the copy or layoutattached to board 1. The layout board 1 is securely attached to thebaseboard 10 and, in order that they may be raised and lowered inregistration with one another, and with the layout-board, the coverframe 2 and backing sheet clamp 4 are attached through hinges 5 to thebaseboard, a preferred form of hinge being hereinafter described withreference to FIGURES 3-5.

By using a hinge it is possible for the cover sheet frame to be liftedinto and out of contact with the backing-sheet or with a mount placedbehind or beside the apparatus. It is also possible to lower the backingsheet onto the working surface a number of times in exactly the sameposition.

For convenience in attaching and replacing the backing sheet, the hingemay incorporate a clamp. A preferred form of backing-sheet clamp andbinge is shown in FIG- URES 35 described below.

An essential component of the apparatus of this invention consists oftwo frames 6 and 7 which, as shown in FIGURE 2 are interconnected bymeans of a hinge 8. Alternatively, the frames could be separate and madeto fiit together in register with a suitable locating device.

Frame -7 termed the transfer frame is provided with a sheet oftransparent film 9 or tracing material onto which an image of the platecan be transferred, which plate is first adhered, face down, to the backof a sheet of copying material secured in the frame 6 termed the holdingframe. Alternatively, the plate holding sheet in the frame 6 need not beof copying material and may be of suificient thickness to obviate thenecessity of a frame to support it, in which case the plate may beattached to it face upwards and a separate carbon sheet inserted or someother copying method used, e.g., the plate could be inked.

In use, the backing sheet 3 is raised to its inoperative position shownin FIGURE 1, and the layout L, which is usually a paste-up from proofsof the plates or blocks to be laid, is placed in a first particularposition on the board 1 and then held in position by adhesive tape andcovered with a sheet of transparent film attached to the cover frame 2.In order to transfer plates to the backing-sheet 3, each plate is firstbacked with double-sided contact adhesive. The next step is to attachthe plates to be laid, one at a time, face downwards to the back of thecarbonised plastic holding sheet in the holding frame 6. Blobs, orstrips of contact adhesive, or stick dots may be used for this purpose.The two frames 6, 7 are then closed or fitted together and turned overso that the plate in the process of being laid is face upunderneaththem, when an image of the plate carried by the sheet of the holdingframe 6 can then be transferred to the transparent film or tracing sheet9 of the second frame 7 by rubbing the film or sheet over the area underwhich the plate lies, with a spatula, roller or any hard object ofsuitable shape and size. The frames 6, 7 are then separated or opened,and the transfer frame 7 now carrying the image, is located with theimage on the transfer sheet 9 exactly over the layout and held inposition, e.g. with adhesive strips. The two frames 6, 7 are then closedor fitted together again so that the plate or block re-registers withthe image on the transfer sheet 9, with the plate face-down in positionover the layout.

Transfer to the backing sheet 3 in a second particular positioncorresponding to the aforesaid first particular position of the layouton the board 1 can now be achieved by removing the protective coveringfrom the double-sided adhesive on the back of the plate and lowering thebackingsheet 3 to its operative position, that is in face-to-faceproximity to the layout board 1, when the plate will adhere to thebacking-sheet being located exactly in the required position by reasonof the correct alignment of its image with that on the layout.Alternatively by lifting the cover frame 2 bodily with the holding frame6 and plate attached to it, it may be raised into contact with thebacking sheet or swung through 180 onto a mounting lying behind orbeside the layout board.

As can be seen from FIGURES 35 the layout board cover frame 2 is fittedwith two arms 34 pivotally attached to two lugs 31 which are fixed tothe baseboard. The clamp bar 4 consists of a strip of channel section 32fitted with set screws 33 and fitted with corresponding arms pivotallyattached to the two lugs 31. The backing sheet 3 is held in the channelstrip 32 by the set screws 33.

Referring now to FIGURES 6 and 7 there is shown a modified arrangementof the holding and transfer frames, the two frames being indicatedrespectively at 16 and 17, the holding frame 16 which is hingedlyinterconnected at 20 to the transfer frame 17 being of a size to fitwithin the confines of frame 17. The holding frame 16 comprises twosheets 18 and 19 each of a size less than the interior dimensions of theframe 16 so that they can be passed through it, being hingedly connectedthereto at 21. Sheet 18 which is of siliconised released paper orsiliconised plastic or metal provides the holding sheet 4 to which theplate is first attached, face up, by means of its adhesive backing.Sheet 19 is the second plateholding sheet and it may be made of thinplastic or metal with contact adhesive blobs or strips on one side.

Having first attached the plate indicated at P to the siliconised sheet13 as described, but face uppermost, the face of the plate is then inkedor a piece of carbon or other copying material placed over it, and theframes are brought together so that the plate lies face up under thetransparent sheet in frame 17. The image is then transferred by rubbing,as previously described, to the transfer sheet in frame 17. After this,frames 16 and 17 are parted so that the image may be located over thelayout and the frame 17 fixed in position by adhesive strips. The frame16, which still carries the plate P is once more located over frame 17,by moving it about its hinge line 20, but with the second holding sheet19 under the front face on the plate and adhering to it. The plate isnow face down in position over the layout and in correct registrationtherewith, being held by both holding sheets. Since the holding sheet 18is hingedly attached to its frame 16, the sheet 18 can now be peeledoff, leaving the plate on the second holding sheet 19, where it appearsback uppermost thus exposing the contact-adhesive. Transfer to thebacking sheet may now be effected as previously described.

Referring now to FIGURE 8 the third form of plate positioning frameconsists of a central transfer frame 21 carrying a transparent (tracing)sheet 21, to which frame 21 is connected by hinges on one side ofholding frame 22 carrying a plastic copying sheet 22 with contactadhesive blobs or strips on the back, and on the other side ofsiliconised release-sheet 23. This positioning frame may either be usedin the manner first described in relation to FIGURES l-2 by attachingthe plate face down to the back of the copying sheet 22 in the holdingframe 22 and then obtaining an image on the transparent sheet 21 whichis then used to register the plate carried by frame 22 with the copy, orwhen it is necessary to ink the plate in order to obtain a satisfactoryimage, it is attached face uppermost by means of its adhesive backing tothe sheet 23, in which case frame 22 performs the function of the secondholding sheet 19 described above, having first folded the sheet 23 andframe 22 with the release sheet 23 innermost so that an image can betraced on sheet 22'.

It will be understood that this form of positioning frame isparticularly suitable for laying colour half-tones where the plate hasto be inked to provide in addition to the outline a detailed image forregistering purposes.

Colour half-tone plates may be laid by this method to transparent proofsof each colour plate pasted up in register, or to a proof of the blackplate.

In some cases, e.g. where exact register is not necessary or where verylarge plates are to be laid, a mould of long, soft paper or board orother suitable material may be made from the plate and positioned overthe layout so that the plate may be laid into it face down and thentransferred to the backing sheet in the manner previously described.With this method the positioning frame is not used.

FIGURE 9 shows an arrangement incorporating a back rest 40, againstwhich the backing sheet 3 can be supported as shown. Back rest 40 ispivotally mounted on trunnion mountings 41 in bracket 42, the latterbeing provided at their upper ends with butterfly headed studs 43 bymeans of which the back rest is supported when in its upright position.By removing the studs 43 the back rest can be swung backwardly to layflat behind the layout board.

What is claimed is:

1. An improved method of laying printing plates or blocks on to abacking sheet or form to conform to a predetermined copy or layout whenplaced on a layout board, the improvement comprising the steps of:

(i) setting up a backing sheet to receive the plates or blocks, saidbacking sheet being capable of movement relative to the layout board;

(ii) attaching a plate to a plate holding means;

(iii) preparing an image transfer sheet to receive an image of saidplate, which transfer sheet is adapted for registration with the plateholding means;

(iv) aligning said transfer sheet with the plate holding means and thenmaking an image of the plate on the transfer sheet;

(v) superimposing said image on its counterpart in the layout board;

(vi) realigning the plate holding means with the image transfer sheet;the plate being positioned face downwards; and transferring the plate tothe backing sheet or direct to the form and repeating the operationuntil all the plates are correctly laid.

2. The method claimed in claim 1 wherein the plate holding meanscomprises a frame having a sheet component, to which plates or blockscan be attached by adhesive.

3. The method claimed in claim 1 wherein the plate holding meanscomprises two sheets for use in conjunction with the image transfersheet and to the second of which sheets the plate is transferred so thatit is held face down-ward prior to transfer to the backing sheet orform.

4. In apparatus for laying printing plates or blocks on to a backingsheet or on to a mount, the combination of (i) a layout board, on towhich the layout or copy is placed;

(ii) a backing sheet to receive plates or blocks from the layout board;

(iii) means interconnecting the backing sheet to the layout board topermit movement of said backing sheet relative to said layout board toan inoperative position to expose said layout board for placement of aplate or block thereon, and permitting movement of said backing sheetrelative to said layoutboard to an operative position registered withand in face-t-o-face proximity to said layout board, whereby saidbacking sheet engages a plate or block 'laid in a first particularposition on said layout board and said plate or block is attachable tosaid backing sheet in a second particular position corresponding to saidfirst particular position;

(iv) a holding means adapted re'leasably to hold a plate or block to belaid;

(v) a transfer means associated with said holding means and capable ofregistration with said holding means, said transfer means including atransparent sheet on which an image of the plate or block can beobtained when said transfer means is in registration with said holdingmeans, said transfer means being positionable in face-to-face proximityto said layout board with said image registering with said layout whensaid backing sheet is in said inoperative position, said holding meanswith said plate or block releasably held thereon being positionable inrel'egist-ration with said transfer means, said plate or block thenregistering with said layout, whereby said backing sheet may be moved toits operative position and said plate or block transferred to saidbacking sheet.

5. Apparatus as claimed in claim 4 in which the holding means comprisesa frame having a sheet for attachment thereto of the plate or block.

6. Apparatus as claimed in claim 5 in which the trans parent sheet isfor-med of carbonised plastic or other copying material.

7. Apparatus as claimed in claim 4 in which the transfer meanscomp-rises a frame mounting said transparent sheet.

8. Apparatus as claimed in claim 4 in which said transfer meanscomprises a pair of hingedly interconnected frames, the first framethereof being provided with a holding sheet and the second frame thereofwith said transparent transfer sheet.

9. A device as claimed in claim 8 in which the first frame is providedwith two sheets, including a holding sheet and an intermediate transfersheet.

10. A device as claimed in claim 9 in which the dimensions of the firstframe are such that when folded against the second frame it fits withinit.

11. Apparatus as claimed in claim 4 :in which said transfer meanscomprises three frames, the two outer frames being hingedly connected toopposite sides of the intermediate frame and being provided respectivelywith a holding sheet and said transparent sheet.

12. Apparatus as claimed in claim 4 in which said layout board isprovided with a clamping device for a backing sheet which device ishingedly attached to the layout board so that the backing sheet can bemoved into and out of its operative position when effecting transfer ofa plate or block thereto.

References Cited UNITED STATES PATENTS 2,428,428 10/'l947 McCarterl0l426 3,000,737 9/196'1' Barnhart 101426 FOREIGN PATENTS 1,132,1546/1962 Germany.

562,505 7/1944 Great Britain.

ROBERT E. PUIJFREY, Primary Examiner. F. A. WINANS, Assistant Examiner.

